Tube rings vs. Dovetail

[multiweb (Marc)]

Just wondering if for a C11 a dovetail bolted into the mirror cell and the corrector cell (as it is standard now) is stiffer than having a dovetail with tube rings around the aluminium tube?

On the same line of thought, I see all RCOS systems have two plates on each sides, no rings so would two plates make the assembly more rigid and less prone to flexure?

The C11 is a fairly heavy scope. Just trying to figure out if the current holding system is enough and flexure free.

As always thanks for your feedback. Much appreciated

[allan gould]

Marc
I have a 10" Meade SCT to which I have affixed Losmandy plates top and bottom. Makes things very rigid. I mounted my guidescope on top with Losmandy attachment that when I want to take it off its very easy, just undo the clamps and it slides off. There is NO flexture in the system.
The bottom plate is for attaching the scope assembly to the mount.
Allan

[[1ponders] (Paul)]

I have the same setup as Allan and we had the same setup on the C11 at the Mapleton Observatory.

[gbeal]

While I am not in the C11 size, I have this unfounded fear of the rail(s) being attached via small lightweight screws, into the alloy rear and front cells. I know this is paranoia, but to me the rings are the way to go.
The RCOS are a different sort of tube assembly, and to compare them is not really relevant I reckon. Plus, why have the top rail, do what I do, mount the finder/guider onto the underside of the saddle, it is essentially a fixture, regardless of the scope in use, it remains with the mount.
Gary

[multiweb (Marc)]

Thanks Guys. I have a spare dovetail that I can use as a traverse for the top. I hear you Gary but the bottom dovetail is a losmandy plate so it fits the G11 profile exactly. The only way it'll go out is by sliding.

With the hyperstar I have been experiencing a slight field tilt over time which I originally attributed to temperature gradients on the corrector but now I'm not so sure. I'm wondering if the whole tube is not flexing due to the weight and being secure only on one side. So possibly the mirror cell could tilt in relation to the corrector cell.

Don't know but something is moving enough to stuff up the field noticeably. So I'm working my way forward with a simple process of elimination with the bits n' pieces I have now. Flex is a b**ch.